#include "apue.h"
#include <sys/wait.h>
#include <unistd.h>
int main()
{
    char    buf[MAXLINE];
    pid_t   pid;
    int     status;

    printf("%% ");
    while (fgets(buf, MAXLINE, stdin) != NULL)
    {
        if (buf[strlen(buf) - 1] == '\n')
        {
            buf[strlen(buf) - 1] = 0;
        }

        if ((pid = fork()) < 0)
        {
            err_sys("fork error");
        }
        else if (pid == 0)
        {
            // child
            execlp(buf, buf, (char*)0);
            err_ret("couldn't execute: %s", buf);
            exit(127);
        }

        // parent
        if ((pid = waitpid(pid, &status, 9)) < 0)
        {
            err_sys("waitpid error");
        }
        sleep(1);
        printf("%% ");
    }
    exit(0);
}
